The function of a jaw crusher is based on a force is compressing the material to be processed. An eccentric shaft is attached to a body of the jaw crusher to which eccentric shaft is connected a movable jaw, i.e. a pitman, making an eccentric movement relative to a fixed jaw.
The movement of the movable jaw is decisive to the capacity and effectiveness of the crusher. The forward movement of the jaw, i.e. the crushing stroke, depends on the movement of the movable jaw and often contains upward and downward movement reducing the efficiency of the stroke.
Previously, improvements to the movement pattern of the movable jaw have been carried out by attaching the pitman to a pivot bar, resulting in a movement pattern having the shape of a flattened oval. Such an arrangement is known from patent application publication WO 2013/171361 A1. However, such an arrangement requires an undesirable amount of space inside the pitman and the crusher frame for the pivot bars and a more complex design requiring careful consideration e.g. in lubrication.
Furthermore, improvements to the movement pattern of the movable jaw have previously been carried out by attaching the pitman to slide member moving in a direction perpendicular to the centerline of the crushing chamber, resulting in a movement pattern having the shape of a flattened oval. Such an arrangement has been disclosed in an unpublished patent application PCT/FI2013/051074.
An object of the invention is to create an alternative crusher by which drawbacks present in connection with known crushers can be eliminated or at least reduced.